MICROPLASTICS IN LANDFILL LEACHATES IN THREE NORDIC COUNTRIES

We investigated the occurrence of microplastics (size range 5,000-50 µm) in leachates at 11 landfills of different age and operational status in Finland, Iceland and Norway. Collective sampling was carried out by pumping leachate with a stainless-steel submergible pump through a custom-made, stainless-steel filter unit containing filter plates with decreasing pore sizes (5,000, 417 and 47 µm, respectively). Samples were pre-treated and split into particles size classes above 500 μm and above 50 μm, and screened for occurrence of microplastics made of PE, PP, PVC, PS, PET, PA, PU, PC, PMMA, POM, SBR (rubber) or PMB (polymer modified bitumen). Samples were analysed by FT-IR spectroscopy, both to identify and to count microplastic particles (SBR and PMB were merely identified). Most samples tested positive for multiple microplastics. Three leachates, including drinking water (blank), tested positive for SBR particles and/or PMB only. Treated leachate samples exhibited lower total microplastic’s counts than untreated, up to several orders of magnitude. National waste management practices over time, landfill age or operational status do not seem to explain differences in microplastic abundance or counts between leachates. Particle count and calculated loads of microplastic emissions through leachates differed several orders of magnitude between landfills. Results indicate that landfill leachates might be a relatively small source of microplastics (>50 µm) to surface waters compared to untreated and treated sewage or road runoff. Continued data acquisition, improved sample preparation and understanding of variability of microplastics in landfill leachate are necessary, including particles smaller than 50 µm.

ASSESSMENT OF THE DEGREE AND SOURCE OF POLYOLEFIN RECYCLATES CONTAMINATION

This study has the aim of analysing the degree of contamination of recycled polyolefin purchased from the market by focusing on the content of polycyclic aromatic hydrocarbons (PAHs). Additionally, the impact of the mechanical recycling process on the polyolefin chemical quality was investigated. Results indicated that recycled polyethylene (PE) had higher PAHs concentrations by 10 to 20 folds in comparison to the pristine PE. Similarly, recycled polypropylene (PP) indicated higher PAHs concentrations in comparison to the virgin polypropylene, yet with lower degree of difference. Analysing the 8 indicators assigned by the Regulation EU 1272/2013 amending REACH Annex XVII, all recycled specimens showed concentrations lower than the limit of 0.5 mg kg-1, which indicates that there is no restriction in material’s utilisation. This study functioned as a preliminary assessment to check the suitability of recycled plastics for their further utilisation. Additionally, the study indicates that polyolefin can experience quality deterioration when uncontrolled recycling conditions are applied.

PREVALENCE OF INJURIES AMONG WASTE PICKERS. A CASE STUDY IN NIGERIA

Waste picking might provide, in low-income countries, a livelihood for many individuals representing an important survival strategy. However, during their activities, waste pickers are at risk of encountering harmful waste, which could cause injuries and other infectious diseases. This paper investigates the occurrences of injury among waste pickers and the methods they use to treat the injuries in Bauchi city, Northeastern Nigeria. A total of 322 waste pickers were randomly selected across 80 waste pickers’ middlemen shops. Data was obtained through questionnaire and interview. Based on the data presented, 1474 frequencies of injuries were reported among 247 waste pickers. Age, education and working experience are significant parameters to the prevalence of injuries among waste pickers, and the incidence of injuries increased with the decrease in those parameters. The study shows that most of the waste pickers experienced injuries, most of whom do not attend clinic when injury occurs; instead, they used salt, ash, sand, hydraulic, kerosene, battery acid, among others, to treat their wounds. Cuts and pierces are good entry points for bacteria and viruses, which can eventually spread to the general public infectious diseases, such as Hepatitis, Cholera and Lassa fever. Provision of Personal Protection Equipment (PPE), a labor rights policy, immunization and the launch of an awareness campaign are among the recommendations made by this study.

BIOCHAR PRODUCTION FROM WASTE BIOMASS: CHARACTERIZATION AND EVALUATION FOR AGRONOMIC AND ENVIRONMENTAL APPLICATIONS

This study focused on the valorization of different types of waste biomass through biochar production at two pyrolysis temperatures (400 and 600°C). The different feedstocks being used included three materials of municipal origin, specifically two types of sewage sludge and the organic fraction of municipal solid waste, and three materials of agroindustrial origin, specifically grape pomace, rice husks and exhausted olive pomace. The scope of the research was to characterize the resulting materials, in order to evaluate their possible uses in agronomic and environmental applications. Biochar characterization included the determination of several physical and chemical parameters, while germination assays were also carried out. Under the investigated conditions, both pyrolysis temperature and feedstock type appeared to significantly affect biochar characteristics, leading to the production of versatile materials, with many different possible uses. Specifically, results implied that biochars of both municipal and agroindustrial origin have the potential to effectively be used in applications including the improvement of soil characteristics, carbon sequestration, the removal of organic and inorganic contaminants from aqueous media, and the remediation of contaminated soil, with the degree of suitability of each material to each specific use being estimated to differ depending on its particular characteristics. For this reason, with these characteristics in mind, before proceeding to larger scale applications a cautious selection of materials should be conducted.

TRANSITION TOWARDS A CIRCULAR ECONOMY: THE ROLE OF UNIVERSITY ASSETS IN THE IMPLEMENTATION OF A NEW MODEL

Public awareness and relevant consumer behaviors are crucial in accelerating the transition to a circular economy (CE) model. This paper focused on exploring university activities for changing awareness and behaviors according to the principles of its new circular model to foster sustainable development. In this paper, a comprehensive literature review provides a holistic perspective on university CE-related activities in the implementation of the CE. The review revealed that the construction of a theoretical framework in universities with asset-based development is conducive to promoting the CE model through transformative learning. In light of recent academic insights into CE education, a theoretical framework for CE-related university activities was developed based on attributes of CE-related university assets, such as non-profit status, technology innovation, education, propagation, and efficient use of resources. We also introduce into scientific use the term CE-related university assets and provide a classification of these CE-related assets. The present findings contribute to a deeper understanding of universities’ CE-related resources and assets to improve public awareness and behaviors, as well as to train and inspire the leaders (including engineers, managers, designers, etc.) of tomorrow, required for further implementing the CE model.

HAZARDOUS PROPERTIES OF BROMINATED, PHOSPHORUS, CHLORINATED, NITROGEN AND MINERAL FLAME RETARDANTS IN PLASTICS WHICH MAY HINDER THEIR RECYCLING

Flame retardants are numerous and some of them are (re)classified with time as hazardous for the man and the environment. A list of 69 flame retardants used in EU was set from three sources and their chemical properties were searched in their registration dossier at ECHA. Substance self-classifications (hazard statement assignment by the registrant) frequently indicate no hazard or data not available, while for the same substances a re-evaluation by ECHA is underway as persistent, bioaccumulative, toxic or endocrine disruptor. When the substance has hazard statement(s), the concentration that triggers the classification of a plastic as hazardous when it is a waste can be compared to the functional concentration, when available. Registration dossiers should be completed for the many “non-available” information. Of these 69 substances, 12 (= 17%) are used at concentrations greater than those making plastic waste hazardous and 13 (= 19%) are under re-evaluation by ECHA. These 12 or 13 substances should not become “legacy” substances which hinder the recycling of plastics. The sorting (mainly by density) and management options of these flame-retarded plastics are discussed. The technical concentration limit of 2000 mg total Br/kg for sorting should not be modified as it includes all organobromine substances currently reassessed by ECHA. A two-step sorting process is necessary to avoid the loss of non-hazardous dense plastics.

Sampling and sub-sampling of granular waste: size of a representative sample in terms of number of particles

This paper elucidates the theoretical principles behind the calculation of the size of a representative sample of granular solid waste. The key concept is the number of particles that must be present in a sub-portion of matter to be representative of a larger portion of matter. This depends on the fraction of particles in the waste batch showing the properties of interest, which shall be measured. A representative sample must include a fraction of particles of interest reliably similar to that of the waste batch to be characterized, with a controlled variability. In this context, it is demonstrated that the number of particles of interest that must be collected in a representative sample is 100. From this requirement, the mass of a representative sample can be calculated based on the knowledge of the frequency of particles of interest of the waste lot to be characterized. Data on particles concentrations in different samples of WEEE plastic scraps exemplifies how the presence in the sample of enough rare particles showing the property of interest is key to ensure reliable measurements. Further, the assumptions made on the controlled degree of variability to determine the minimum number of particles are discussed based on data on achievable intra- and inter-laboratory variability of analytical standards for waste characterization. Accordingly, the mass of laboratory samples and test portions recommended in published sampling plans or analytical standards are assessed for the occurring number of particles.